| Author |
Message |
    
Cavebear
cave painter
Username: Cavebear
Post Number: 3030
Registered: 9-2003
| | Posted on Monday, November 13, 2006 - 12:29 am: |     |
Ayla wasn't blonde (see sidebar notes below)!
The NewScientist magazine November 4-10, 2006 issue has an article on human hair. I can't seem to link to the online article (online subscription required).
All hair on most mammals grows to a certain length, goes dormant, and then falls out. Humans and musk ox are the only mammals with some continuously-growing hair.
Apparently, humans have the gene for continuously-growing head hair but it is the pseudogene "phi-hHaA" (transmitted but does not synthesize a protein to express itself) that originated about 240,000 years ago. The one suggestion is that our growing head hair served as a social status marker. High-ranking individuals would get enough grooming to keep long hair neat (displaying their high status). The conclusion is that we have long head hair only so that it can be cut and coiffed...
Other suggestions involve the lack of need for long body hair due to clothing and thermo-regulation (efficient sweating/cooling); head hair for sun protection, sexual selection, and even semi-aquatic living.
Among the other interesting sidebar notes:
1. The first blondes appeared around 11,000 years ago.
2. We have about the same number of bodily hairs as other primates (5 million).
3. The number of head hairs depends on hair color (blondes, 140,000; brunettes, 105,000; redheads, 90,000).
Thank you, Carl Sagan... |
Scott
flint knapper
Username: Scott
Post Number: 1607
Registered: 5-2003
| | Posted on Wednesday, November 15, 2006 - 5:44 am: | |
Perhaps she used dye? Peroxide?
Thanks for the info. The rest of our hair doesn't keep growing - which is a relief. Imagine having to get your underarm hair coiffed every 6 weeks? 
Does the article say anything about when red hair originated?
Scott
~ ~ ~ ~ ~ ~ ~ ~
Ces gens, Jondalar, ils sourient. Ils me sourient. - Ayla |
Cavebear
cave painter
Username: Cavebear
Post Number: 3038
Registered: 9-2003
| | Posted on Wednesday, November 15, 2006 - 7:11 pm: | |
The NewScientist article does not mention an age for red-hair, but I did find a reference on another website for 20 kya. It didn't support the claim, though.
I did find that the same pigmentation mutation seems to connect blonde through red hair, so they might be closely related in origin.
The interesting thing I found was 2 "theories" for the origin of the mutation(s). One was an increase in vitamin D intake. The other was sexual selection pressures in Europe. Both are predicated on an initial loss of melanin, so lighter skin came first.
The site that mentioned the vitamin D connection seemed a bit confusing, and admitted it could not explain Inuit hair color being dark. I lost track of that site, so I can't post it.
The sexual selection idea seems more intriguing. It postulates that light hair came along with lighter skin (loss of melanin), and that blonde/red hair originated in women:
1. Retreating glaciers in Europe created the first environment where foraging was not a successful food-gathering strategy (the plants that grew back were more suitable for herbivores than humans).
2. The women stayed in camp and focussed on preparing food and shelter.
3. The men spent more time and effort hunting animals.
4. The women died less often, the men more often.
5. A gender imbalance developed (more women than men).
6. A competition for male mates encouraged differences among women.
7. Minor physical differences among women had greater advantages.
8. Hair color was a very distinctive difference.
9. Sexual selection magnified those physical traits.
The idea that it occurred in Europe was quite interesting, and I had to think about that for a while. After all, glaciers retreated in North America and Asia, too. It finally struck me that Europe is short north/south. While a small percentage of land was exposed by the retreating glaciers in Asia, a very large percentage of Europe was exposed. The humans expanding into the newly-exposed areas of Europe were a larger part of the regional gene pool there. Mutations had a better change of surviving.
Thank you, Carl Sagan... |
Pine
flint knapper
Username: Pine
Post Number: 1280
Registered: 5-2003
| | Posted on Wednesday, November 15, 2006 - 9:04 pm: | |
OK, so this places a timeline and reasoning for reversal od mate selection in humans. Though there is still a lot of the more common kind (males competing for females). I wonder how far from 1:1 the sex ratio ever got.
Cohen's Law: 'Unless you fail at more than 10% of the things you try, you aren't trying enough things.' |
Cavebear
cave painter
Username: Cavebear
Post Number: 3044
Registered: 9-2003
| | Posted on Wednesday, November 15, 2006 - 10:12 pm: | |
The sites I read didn't say. And, it does seem the arguments were more logical that evidential. That doesn't make the strongest argument.
But I did think it was a reasonable idea and one that might be able to be studied some day. It seems to depend on the idea that foraging was less successful than in the past do to the types of the plants that most quickly re-colonized the exposed retreating glacial environment. I think that makes some sense.
Someone who studies paleopollen could probably support or deny the idea with some authority. I sure can't.
I can see an analogy in modern times. In the US, african-american women outnumber available african-american men in most cities. There are some similar responses going on in the search for mates. Africa-american women have changed their strategies for attracting mates.
It works the other way, too, of course. In the early US colonial period, there were many fewer females than males, and that had consequences. Women who never would have attracted a mate back home were in high demand in the colonies. The same thing happened later in the US Western frontier.
I dare suggest that, after major wars, there are few unmarried men (there being some percentage fewer of them compared with women). There are temporary imbalances, and usually for identifiable reasons...
Thank you, Carl Sagan... |
Sweetsunray
storyteller
Username: Sweetsunray
Post Number: 1124
Registered: 9-2003
| | Posted on Thursday, November 16, 2006 - 12:07 am: | |
Hmmm, my best friend today mentioned how he once stopped an argument on ID...
How can there be ID when there's a "hairy ass"? I'd rather want to slap that designer.
Everyone has a motive for giving arguments. But only the arguments given matter. |
Cavebear
cave painter
Username: Cavebear
Post Number: 3046
Registered: 9-2003
| | Posted on Thursday, November 16, 2006 - 1:16 am: | |
SSR - There are many "Unintelligent Design" arguments.
Thank you, Carl Sagan... |
Sweetsunray
storyteller
Username: Sweetsunray
Post Number: 1125
Registered: 9-2003
| | Posted on Thursday, November 16, 2006 - 2:27 am: | |
I know... but that one fit in here And from what he told me, the debate about ID ended, and proceeded on the hairiness of the butt. 
Everyone has a motive for giving arguments. But only the arguments given matter. |
Ted
hunter
Username: Ted
Post Number: 517
Registered: 5-2004
| | Posted on Thursday, November 16, 2006 - 7:21 am: | |
(Pine)
Though there is still a lot of the more common kind (males competing for females).
That's strange, I thought a man chased a woman until she caught him..........
Ted
Do not go gentle into that good night...Rage, rage against the dying of the light
Benjamin Disraeli: "The Jews are a nervous people. Nineteen centuries of Christian love have taken a toll." |
Cavebear
cave painter
Username: Cavebear
Post Number: 3047
Registered: 9-2003
| | Posted on Thursday, November 16, 2006 - 7:56 am: | |
It varies through time, Ted. Apparently, we sometimes actually choose them !
Thank you, Carl Sagan... |
Thales
gatherer
Username: Thales
Post Number: 127
Registered: 9-2003
| | Posted on Thursday, November 16, 2006 - 4:36 pm: | |
Cavebear: "I dare suggest that, after major wars, there are few unmarried men"
Take a look at the history of Paraguay. The country has fought two wars each of which destroyed almost the entire male population (Paraguay won at least one of those wars, the latter IIRC). According to Danish journalist Arne Falk-Rønne, the remaining men didn't marry at all, for some time at least they just rode around the country doing the only thing women couldn't do.
“The ability to quote is a serviceable substitute for wit.” |
Sweetsunray
storyteller
Username: Sweetsunray
Post Number: 1126
Registered: 9-2003
| | Posted on Thursday, November 16, 2006 - 10:58 pm: | |
Wondering what will happen in Bangladesh, India and Chinain that regard. There will be a coming generation of men who won't be able to marry because of shortage of women (99% of abortions are female foetuses to avoid paying a dowry for a daughter). I fear though it won't change into a polyandry society, but one where rape will be highly common.
Bangladesh men already react violently on rejection by women, and throwing acid in their faces is becoming a common revenge tactic by the men.
Everyone has a motive for giving arguments. But only the arguments given matter. |
Cavebear
cave painter
Username: Cavebear
Post Number: 3053
Registered: 9-2003
| | Posted on Friday, November 17, 2006 - 9:53 pm: | |
Thales, I think that a shortage of available males causes a temporary breakdown in the usual marriage pattern. It seems to mean (no judgement made) that women will take the best deal they can get to have babies. Sometimes it is a good stable arrangement, sometimes not. But it allows the men to just "tomcat" around.
Interestingly (again, no judgement made) when men outnumber women, the women turn it to an economic advantage.
Thank you, Carl Sagan... |
Cavebear
cave painter
Username: Cavebear
Post Number: 3054
Registered: 9-2003
| | Posted on Friday, November 17, 2006 - 9:59 pm: | |
SSR - I agree that the violent response of men in the lack of mates is a problem that will challenge those societies where there are many fewer women than men.
The solution may seem obvious (reverse the dowry demands, discourage the abortion or infanticide of female babies, etc) but cultural changes come slowly, and tradition gets in the way.
Education seems to be the fastest way of changing such attitudes.
Thank you, Carl Sagan... |
Sweetsunray
storyteller
Username: Sweetsunray
Post Number: 1128
Registered: 9-2003
| | Posted on Sunday, November 19, 2006 - 7:00 pm: | |
And especially those who have the most (financially and powerwise), in this case the Brahmans, are least of all eager to change things.
Everyone has a motive for giving arguments. But only the arguments given matter. |
Cavebear
cave painter
Username: Cavebear
Post Number: 3064
Registered: 9-2003
| | Posted on Monday, November 20, 2006 - 7:41 pm: | |
SSR - I agree that those with the most to lose from changes are usually the most resistant to those changes. I think most changes come from the bottom up (sometimes encouraged by a minority of the elite).
What baffles me, though, is when beneficial changes are most resisted by those on the bottom. "Tradition" is a powerful but seemingly counter-inutitive force.
Thank you, Carl Sagan... |
Scott
flint knapper
Username: Scott
Post Number: 1627
Registered: 5-2003
| | Posted on Tuesday, November 21, 2006 - 7:53 pm: | |
I understand that China is now encouraging two children families in some cases.
What's wrong with hairy asses SSR? ;p
Ted, that has been my experience!
I wonder if, after a war, women also see men as "damaged goods" somehow? If you were/are a woman, would you jump into a marriage with a Vietnam/Iraq/Afghanistan vet? I am not sure of the answer, just wondering.
I have to take issue with #4 cavebear. How did they come to the idea that men died more often than women? Apart from starvation and resource stress issues affecting longevity, I would still suspect that childbirth was at least as dangerous as "hunting" for men was.
Scott
~ ~ ~ ~ ~ ~ ~ ~
Ces gens, Jondalar, ils sourient. Ils me sourient. - Ayla |
Sweetsunray
storyteller
Username: Sweetsunray
Post Number: 1129
Registered: 9-2003
| | Posted on Tuesday, November 21, 2006 - 9:25 pm: | |
I'd have to ask my friend... Women tend to be less hairy overall
Everyone has a motive for giving arguments. But only the arguments given matter. |
Cavebear
cave painter
Username: Cavebear
Post Number: 3072
Registered: 9-2003
| | Posted on Wednesday, November 22, 2006 - 10:43 pm: | |
Scott - I think the ratio of men to women is almost impossible to prove evidentially in prehistoric times. Maybe there were always more adult men (from female childbirth deaths) or always more women than men (through male hunting or territory-protection deaths).
But the idea seems to be that when glaciers retreated in Europe, the newly-exposed land was more suitable to hunting animals than to foraging for plant foods. From what I understand of historic hunter-forager tribes, the men hunt animals and the women gather plants.
So, when foraging for edible plants was not very effective (there being few of them), the women spent more time in camp, improving conditions there. Life in camp meant fewer predations of women. At the same time, the lack of plants as food meant that men had to spend more time hunting animals. More hunting means more injuries (and perhaps more predation by lions and tigers and bears (oh my).
Death by childbirth wouldn't have changed for women, but death by hunting likely would have increased for men (just a function of more time spent at it). Whatever the ratio of men to women was before, it would have decreased the number of men to some degree after they had to start hunting more often.
That seems to be the reasoning, anyway.
Thank you, Carl Sagan... |
Pine
flint knapper
Username: Pine
Post Number: 1296
Registered: 5-2003
| | Posted on Wednesday, November 22, 2006 - 11:18 pm: | |
But we know of recent societies that followed this lifestyle - Inuit, Native Americans of the Great Plains. What were their sex ratios at different ages?
Cohen's Law: 'Unless you fail at more than 10% of the things you try, you aren't trying enough things.' |
Cavebear
cave painter
Username: Cavebear
Post Number: 3079
Registered: 9-2003
| | Posted on Thursday, November 23, 2006 - 12:34 am: | |
Pine, I'm not sure what you mean. Could you elaborate?
Thank you, Carl Sagan... |
Pine
flint knapper
Username: Pine
Post Number: 1298
Registered: 5-2003
| | Posted on Thursday, November 23, 2006 - 4:07 am: | |
The lifestyle of Great Plains Indians, especially in the more northern areas, would have been similar to the lifestyle of the people described in the article. Mostly based on big game hunting, and the colder the climate the lower the proportion of gathered plant food in the diet. What does the sex ratio at different ages look like for such a population? At what age are there excess females? (Even without records, information should be available from burial sites.)
Cohen's Law: 'Unless you fail at more than 10% of the things you try, you aren't trying enough things.' |
Cavebear
cave painter
Username: Cavebear
Post Number: 3082
Registered: 9-2003
| | Posted on Thursday, November 23, 2006 - 5:02 am: | |
We can't measure information from ancient Amer-Indian burial sites. It is forbidden by law.
But I will point out that the proportion of land exposed by retreating glaciers in North America was much less than the proportion of land exposed in Europe. That is part of the hypothesis.
Thank you, Carl Sagan... |
Science Lab